Film cutting machine and method for cutting a protective film

Abstract

The application discloses a film cutting machine, which comprises a rack, a detachable material roller and a rotatable rubber roller installed on the rack, the material roller and the rubber roller being arranged in front and back, a variable frequency motor installed on the rack, one end of the rubber roller being fixedly connected with an output shaft of the variable frequency motor, and the variable frequency motor being stopped when the length of a protective film pulled from the material roller by the rubber roller reaches a preset length. The application also discloses a protective film cutting method, wherein the protective film material roller is installed on the film cutting machine, and the film cutting machine cuts protective films of different lengths according to a preset cutting sequence. The film cutting machine of the application realizes the function of automatic and accurate film cutting by controlling the variable frequency motor through a computer, and compared with the method of cutting protective films by visual observation, the method of controlling the computer and the roller encoder to output the protective film not only improves the cutting speed of the protective film, but also reduces the consumption of the protective film, thereby avoiding unnecessary waste.

Description

Technical Field

[0001] This invention belongs to the field of cutting equipment technology, and relates to film cutting machines. Background Technology

[0002] When new gasoline-powered and electric vehicles leave the factory, a paint protection film is usually applied to areas such as the engine hood, roof, and trunk lid to prevent damage to the exterior paint.

[0003] Paint protection film is a protective measure applied to the surface of a car body to prevent paint damage during transportation. When the car leaves the factory, the staff cuts a protective film with an area that matches the area of ​​the car body that needs to be covered (such as the engine hood) from the protective film cutting machine, and then applies the protective film to the car body.

[0004] When cutting protective film, workers typically take a simple measurement of the vehicle's engine hood, pull a roughly suitable length of film from the film cutting machine, and then cut the film using the machine's blade. In other words, existing film cutting machines cannot accurately control the film length, so workers usually rely on their senses and experience to judge whether the cut film is the correct length. If the cut film is too short, it will not cover the area of ​​paint to be protected, requiring recutting. Therefore, workers tend to cut the film longer, often resulting in unnecessary waste. Summary of the Invention

[0005] The purpose of this invention is to provide a film cutting machine that can cut protective films of a corresponding length according to a preset length, thereby avoiding unnecessary waste.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A film cutting machine includes a frame on which a detachable material roller and a rotatable rubber roller are mounted. The material roller and the rubber roller are arranged front to back. The machine also includes a variable frequency motor mounted on the frame. One end of the rubber roller is fixedly connected to the output shaft of the variable frequency motor. When the length of the protective film pulled by the rubber roller from the material roller reaches a preset length, the variable frequency motor stops operating.

[0008] Optionally, it also includes a control computer, which is communicatively connected to the variable frequency motor.

[0009] Optionally, a rodless cylinder is fixedly installed at the front of the stand, and a cutter is fixedly installed on the slide of the rodless cylinder; the rodless cylinder is communicatively connected to the control computer.

[0010] Optionally, a roller encoder is fixedly connected to the rear of the stand, the roller surface of the roller encoder is tangent to the protective film wound on the rubber roller, and the roller encoder is communicatively connected to the control computer.

[0011] Optionally, the platform includes a platform and multiple support legs. The platform is fixedly installed on the top of the multiple support legs, and mounting plates are fixedly installed at both ends of the platform. The material roller and the rubber roller are mounted on the two mounting plates.

[0012] Optionally, a ruler is fixedly installed on the support leg on the front side of the platform.

[0013] Optionally, one or more pointers are slidably mounted on the scale.

[0014] Optionally, a horizontally opening U-shaped bracket is fixedly installed on the support leg on the front side of the platform, and a through-beam grating is installed on the U-shaped bracket.

[0015] Optionally, the through-beam grating includes a transmitter and a receiver, the transmitter and the receiver being fixedly mounted inside two opposing side rods of the U-shaped bracket.

[0016] Optionally, it also includes an LED display screen mounted on a stand, the LED display screen being communicatively connected to the receiver.

[0017] The present invention also provides a method for cutting protective film, comprising: installing a protective film roller onto any of the film cutting machines described above, and cutting protective films of different lengths according to a preset cutting sequence.

[0018] Optionally, the step of cutting protective films of different lengths according to a preset cutting order includes cutting three different lengths of protective film, which are respectively adapted to the vehicle's engine hood, roof cover, and trunk lid.

[0019] Optionally, the step of cutting protective films of different lengths according to a preset cutting sequence includes cutting two different lengths of protective film, the two different lengths of protective film being adapted to the vehicle's engine hood and roof cover respectively.

[0020] The beneficial effects of this invention include:

[0021] 1. The film cutting machine disclosed in this invention can be set by the control computer to cut protective films of different lengths and can set the output sequence of protective films of different lengths. Therefore, it can realize the function of automatically and accurately outputting the appropriate length of protective film each time. Compared with the method of cutting protective film by visual inspection, controlling the output of protective film by the control computer not only improves the cutting speed of protective film, but also reduces the waste of protective film.

[0022] 2. This invention adds a ruler or through-beam grating to the film cutting machine to measure the length of the protective film output by the film cutting machine. This allows the operator to further verify the length of the protective film output by the film cutting machine when operating the film cutting machine to obtain the protective film, thereby improving the accuracy of the output protective film length of the film cutting machine. At the same time, it can reduce operator errors and avoid errors such as cutting protective film that does not meet the vehicle's requirements. Attached Figure Description

[0023] Figure 1 This is a side view of the internal structure of an optional embodiment of the film cutting machine of the present invention.

[0024] Figure 2 yes Figure 1 The front view of the embodiment shown.

[0025] Figure 3 This is a side view of the internal structure of another optional embodiment of the film cutting machine of the present invention.

[0026] Figure 4 yes Figure 3 The front view of the embodiment shown.

[0027] In the diagram: 1. Tabletop; 2. Mounting plate; 3. Rubber roller; 4. Material roller; 5. Roller encoder; 6. Variable frequency motor; 7. Guide rail box; 8. Control computer; 9. Ruler; 10. Pointer; 11. Through-beam grating. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] See attached document Figure 1-4 A film cutting machine includes a frame, the frame including a horizontally extending table panel 1, with the length direction of the table panel 1 defined as transverse and the width direction as longitudinal. A support structure is also connected to the bottom surface of the table panel 1, the support structure including four vertically extending support rods, the top ends of the four support rods being fixedly connected to the bottom surface of the table panel 1 near the four apex corners, providing stable support for the table panel 1. A horizontal rod is also fixedly connected between opposing support rods to increase the stability of the support structure.

[0030] Both ends of the table panel 1 are fixedly connected to mounting plates 2 extending vertically. The two mounting plates 2 have U-shaped slots with upward openings. The roller shaft of the material roller 4, which is wound with a protective film, can be installed in the slot and can rotate in the slot, making it easy to pull out the protective film.

[0031] Furthermore, a rubber roller 3 parallel to the material roller 4 is also installed on the frame. Specifically, the rubber roller 3 is positioned between two mounting plates 2, and both ends of the rubber roller 3 are rotatably connected to the two mounting plates 2 respectively. The rubber roller 3 is positioned behind the material roller 4. After the new protective film material roller 4 is installed into the slot, the end of the protective film is wound around the surface of the rubber roller 3 from above, and then unwound from below the rubber roller 3, and finally pulled out from below the material roller 4. Compared to directly pulling the protective film from the material roller 4, winding the protective film around the rubber roller 3 before pulling it out increases the resistance to pulling the protective film. This allows the pulling speed of the protective film to be limited, keeping the protective film taut during the pulling process.

[0032] Furthermore, since winding the protective film onto the rubber roller 3 increases the pulling resistance of the protective film, directly pulling the protective film manually can easily cause excessive force and deformation, affecting its use. Therefore, a variable frequency motor 6 is also installed on the frame to drive the rubber roller 3 to rotate. The pulling speed of the protective film can be controlled by controlling the rotation speed of the variable frequency motor 6. Specifically, the output shaft of the variable frequency motor 6 is fixedly connected to one end of the rubber roller 3. When obtaining the protective film, the end of the protective film is tightened, and then the variable frequency motor 6 is started, causing the variable frequency motor 6 to drive the rubber roller 3 to rotate and pull the protective film from the material roller 4, allowing the operator to easily obtain the required protective film.

[0033] It is important to note that when pulling the protective film, the rotation speed of the variable frequency motor 6 should be controlled to keep the rubber roller 3 at a relatively gentle rotation speed. This ensures that the protective film is pulled taut, maintaining its flatness and improving the smoothness of the pulling process. It also allows for better control of the pulling speed, ensuring efficient film pulling while avoiding excessive speed that could lead to excessively long film pulling or damage to the protective film.

[0034] Furthermore, the film cutting machine also includes a control computer 8, which is communicatively connected to the variable frequency motor 6. Control commands are input to the control computer 8, which then controls the start and stop of the variable frequency motor 6. Specifically, the control computer controls the start and stop of the variable frequency motor 6 based on a pre-inputted length of the protective film to be obtained. When the length of the pulled protective film reaches the preset length value in the control computer 8, the control computer 8 sends a stop signal to the variable frequency motor 6, and the variable frequency motor 6 stops rotating. After the variable frequency motor 6 stops, the resistance to pulling the protective film will increase significantly, and the operator will feel a noticeable pause. At this point, the operator can cut the protective film. Of course, the speed of the variable frequency motor 6 can also be set by the control computer 8, thus controlling the speed of the variable frequency motor 6.

[0035] The film cutting machine is also equipped with a cutting mechanism for cutting the protective film. The cutting mechanism includes a guide rail box 7 fixedly installed on the front side of the table panel 1. The guide rail box 7 is approximately rectangular in shape and hollow inside. A transverse through-hole extending laterally is formed on the top plate of the guide rail box 7. A rodless cylinder is installed inside the guide rail box 7, and a cutter is fixedly installed on the slide of the rodless cylinder. The upper part of the cutter extends out of the transverse through-hole at the top of the guide rail box 7. When it is necessary to cut the protective film, the rodless cylinder drives the cutter to cut the protective film. It should be noted that the length of the guide rail box 7 is greater than the width of the protective film, and the length of the transverse through-hole is also greater than the width of the protective film. Furthermore, when not in operation, the cutter is always located at one end of the transverse through-hole to ensure that the cutter can completely cut the protective film. The rodless cylinder is communicatively connected to the control computer 8, meaning that the operation of the rodless cylinder is controlled by the control computer 8.

[0036] The length of the protective film cut from the film cutting machine must be compatible with the dimensions of the car's engine hood and roof. Therefore, the film cutting machine is equipped with a roller encoder 5 for measuring the length of the pulled protective film. Specifically, a bracket is fixedly installed on the rear side of the platform 1, and the roller encoder 5 is mounted on the top of the bracket. The roller surface of the roller encoder 5 is in contact with the surface of the protective film wound on the rubber roller 3. The movement of the protective film will drive the roller of the roller encoder 5 to rotate, and the length of the protective film pulled is consistent with the length of the roller surface of the roller encoder 5 rolling. Therefore, the roller encoder 5 can realize real-time measurement of the length of the protective film pulled. The roller encoder 5 is communicatively connected to the control computer 8. Specifically, if the required length of the protective film to be cut is L, the cutting length of the protective film is set to L through the input device of the control computer 8. After the film cutting machine is started, the operator stretches the protective film, and the variable frequency motor 6 drives the rubber roller 3 to rotate. When the roller encoder 5 measures the length of the protective film pulled out to be L, it sends an electrical signal to the control computer 8 indicating that the length of the protective film pulled out has reached the preset value L. At this time, the control computer 8 sends a stop command to the variable frequency motor 6, and the variable frequency motor 6 immediately stops rotating. Simultaneously, the control computer 8 sends an action command to the rodless cylinder, and the slider of the rodless cylinder drives the cutter to cut the protective film, completing the cutting of the protective film. By using the control computer 8 to automate the cutting of the protective film, not only can the cutting efficiency of the protective film be improved, but also the waste of protective film can be significantly reduced.

[0037] It is important to note that when applying protective film to a vehicle, the protective film is typically applied sequentially to the hood, roof, and trunk lid of the same vehicle. That is, the protective film is first cut for the hood, applied to the hood, then cut for the roof, applied, and finally applied to the trunk lid. Since the required lengths of the protective film for the hood, roof, and trunk lid are different, the cutting values ​​for the three protective film lengths need to be set sequentially in the control computer 8. Therefore, the sizes of the protective film removed from the film cutting machine are, in order, those for the hood, roof, and trunk lid.

[0038] As mentioned earlier, the film cutting machine is configured to sequentially cut three lengths of protective film according to a preset cutting order to obtain protective films for the car engine hood, roof, and trunk lid, respectively. The film cutting machine measures the length of the protective film passing through the rubber roller 3 using a roller encoder 5. After multiple uses, the cumulative error of the roller encoder 5 increases, causing the output protective film length to not meet the requirements. Therefore, it is necessary to verify the length of the protective film cut by the film cutting machine. This is to avoid waste caused by a mismatch between the protective film length and the actual required length, and also to calibrate the film cutting machine. Therefore, a length measuring device capable of assisting in measuring the length of the protective film being pulled is also needed.

[0039] In an optional embodiment, a scale 9 extending vertically is fixedly installed on the support leg at the front of the frame. The scale 9 is engraved with graduations distributed vertically. Since the relative position of the cutter and the support leg remains unchanged, the relative position between the end of the remaining protective film after each cut, i.e., the cut surface of the remaining protective film, and the support leg is approximately the same. Therefore, when the operator pulls the protective film, they can determine the approximate length of the protective film by observing the approximate position of the end of the protective film on the scale 9, thereby knowing the size of the protective film output by the film cutting machine at this time, and thus determining whether the output film length of the film cutting machine matches the required protective film length.

[0040] Furthermore, to facilitate the observation of the length of the protective film output by the film cutting machine by the operator using the ruler 9, one or more pointers 10 are provided on the ruler 9 that can slide along the ruler 9. The orientation of the pointers 10 is parallel to the scale on the ruler 9. Specifically, in this embodiment, three pointers 10 slide sequentially from top to bottom on the ruler 9. The positions of the three pointers 10 on the ruler 9 correspond to the length of the protective film output by the film cutting machine for use on car engine hoods, roofs, and trunk lids. Therefore, the operator can more easily determine the length of the protective film output by the film cutting machine each time, and it is more convenient for the operator to check the length of the cut protective film.

[0041] In another optional embodiment, a through-beam grating 11 for measuring the length of the film cutting machine is mounted on the support leg. Specifically, a U-shaped bracket is fixedly mounted on one of the support legs on the front side of the platform. The two opposing side rods of the U-shaped bracket are located on the same horizontal plane, and the emitter and receiver of the through-beam grating 11 are respectively mounted inside the two opposing side rods of the U-shaped bracket. When the protective film is pulled out, the protective film enters the area between the emitter and the receiver. Since the infrared light emitted by the emitter is blocked by different lengths of protective film, the infrared light signal received by the receiver will also be different, thus allowing the length of the protective film output by the film cutting machine to be measured.

[0042] In this embodiment, an LED display screen is also provided on the frame. The LED display screen is electrically connected to the through-beam grating 11. The LED display screen can display the length of the protective film measured by the through-beam grating 11 in real time. The operator can know the length of the protective film output by the film cutting machine by looking at the value on the LED display screen. Optionally, the LED display screen is fixedly mounted on a mounting plate on one side.

[0043] The present invention also discloses a method for cutting protective film. The method includes the steps of installing a protective film roller 4 onto the film cutting machine described above, and the film cutting machine cutting protective film of different lengths from the roller 4 according to a preset cutting sequence.

[0044] Specifically, the step of installing the protective film roller 4 onto the film cutting machine described above includes installing the roller shaft of the roller 4 into the slot on the mounting plate 2. The roller 4 can rotate within the slot, and then the protective film on the roller 4 is wrapped around the rubber roller 3 and pulled out from under the roller 4. Subsequently, the protective film is continuously pulled out. When the protective film is pulled out, the variable frequency motor 6 drives the rubber roller 3 to rotate. When the protective film pulling length measured by the roller encoder 5 reaches the preset length in the control computer 8, the control computer 8 sends a stop command to the variable frequency motor 6 and starts the rodless cylinder. The rodless cylinder drives the cutter to complete the cutting of the protective film.

[0045] The step of the film cutting machine cutting protective films of different lengths from the material roller 4 according to a preset cutting sequence includes sequentially cutting multiple protective film lengths of different lengths.

[0046] In an optional embodiment, when the vehicle to be covered is a vehicle with a trunk lid, that is, the engine hood, roof, and trunk lid of the vehicle need to be covered with protective film. The preset protective film cutting sequence includes cutting three different lengths of protective film in sequence, which are respectively adapted to the engine hood, roof, and trunk lid of the vehicle. In other words, the preset protective film cutting sequence is the same as the vehicle's protective film application sequence, so that the operator can complete the application of protective film to the engine hood, roof, and trunk lid of the vehicle in sequence.

[0047] In another optional embodiment, when the vehicle to be covered is one without a trunk lid, that is, the engine hood and roof of the vehicle need to be covered with protective film. The preset order of cutting the protective film includes cutting two different lengths of protective film in sequence, which are respectively adapted to the engine hood and roof of the vehicle, so that the staff can complete the application of protective film to the engine hood and roof of the vehicle in sequence.

[0048] Optionally, the control computer is a Siemens S-200 series programmable logic controller (PLC).

[0049] It should be noted that the communication connection mentioned above refers to the information exchange and electrical signal transmission between the control computer 8 and the variable frequency motor 6, the rodless cylinder, and the roller encoder 5 through a wireless communication protocol. This wireless communication protocol can be one or more of the following: ZigBee, Wi-Fi, and Bluetooth. In another embodiment, the control computer 8 and the variable frequency motor 6, the rodless cylinder, and the roller encoder 5 can also achieve data exchange and communication through a data cable.

[0050] The foregoing descriptions and embodiments are provided to enable those skilled in the art to understand and apply the present invention. It will be apparent to those skilled in the art that various modifications can be easily made to these contents, and the general principles described herein can be applied to other embodiments without creative effort. The present invention is not limited to the foregoing descriptions and embodiments; any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from its scope should be within the protection scope of the present invention.

Claims

1. A film cutting machine, comprising a frame, on which a detachable material roller and a rotatable rubber roller are mounted, the material roller and the rubber roller being arranged front and rear, characterized in that: It also includes a variable frequency motor mounted on the frame, one end of the rubber roller is fixedly connected to the output shaft of the variable frequency motor, and the variable frequency motor stops operating when the length of the protective film pulled by the rubber roller from the material roller reaches a preset length; a horizontally opening U-shaped bracket is fixedly mounted on the support leg on the front side of the frame, and a through-beam grating is mounted on the U-shaped bracket; the through-beam grating includes a transmitter and a receiver, and the transmitter and the receiver are respectively fixedly mounted inside two opposite side rods of the U-shaped bracket.

2. The film cutting machine according to claim 1, characterized in that: It also includes a control computer, which is communicatively connected to the variable frequency motor.

3. The film cutting machine according to claim 2, characterized in that: A rodless cylinder is fixedly installed at the front of the frame, and a cutter is fixedly installed on the slide of the rodless cylinder; the rodless cylinder is communicatively connected to the control computer.

4. The film cutting machine according to claim 3, characterized in that: A roller encoder is fixedly connected to the rear of the stand. The roller surface of the roller encoder is in contact with the protective film wound on the rubber roller. The roller encoder is communicatively connected to the control computer.

5. The film cutting machine according to claim 4, characterized in that: The frame includes a platform and multiple support legs. The platform is fixedly installed on the top of the multiple support legs. Mounting plates are fixedly installed at both ends of the platform. The material roller and the rubber roller are mounted on the two mounting plates.

6. The film cutting machine according to claim 1, characterized in that: It also includes an LED display screen mounted on a stand, which is communicatively connected to the receiver.

7. A method for cutting a protective film, characterized in that, include: The steps of installing the protective film roller onto the film cutting machine according to any one of claims 1 to 6, and cutting protective films of different lengths according to a preset cutting sequence.

8. The method for cutting the protective film according to claim 7, characterized in that: The step of cutting protective film of different lengths according to a preset cutting order includes cutting three different lengths of protective film, which are respectively adapted to the engine hood, roof cover and trunk lid of the vehicle.

9. The method for cutting the protective film according to claim 7, characterized in that: The step of cutting protective films of different lengths according to a preset cutting sequence includes cutting two protective film lengths of different lengths, which are respectively adapted to the engine hood and roof of the vehicle.

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